diff --git a/lib/Kalamar/API.pm b/lib/Kalamar/API.pm
new file mode 100644
index 0000000..8cc1d41
--- /dev/null
+++ b/lib/Kalamar/API.pm
@@ -0,0 +1,493 @@
+package Kalamar::API;
+use Mojo::Base 'Mojolicious::Plugin';
+use Scalar::Util qw/blessed weaken/;
+use strict;
+use warnings;
+
+# KorAP Search engine for Mojolicious::Plugin::Search
+
+# Todo: Add fixtures
+# Todo: Support search in corpus and virtualcollection
+# Todo: Support caching everywhere!
+# Todo: Correct use of stash info everywhere!
+
+# Register the plugin
+sub register {
+  my ($plugin, $mojo, $index_class, $param) = @_;
+  $param ||= {};
+
+  # Add attributes to the index class
+  $index_class->attr(api => $param->{api});
+  $index_class->attr([qw/cutoff
+			 query_language
+			 time_exceeded
+			 api_request
+			 _api_cache
+			 api_response
+			 benchmark
+			 query_jsonld/]);
+  $index_class->attr(no_cache => 0);
+};
+
+
+# Search the index
+sub search {
+  my $self = shift;
+  my $index = shift;
+
+  # Get controller
+  my $c = $index->controller;
+
+  # If there is a callback, do async
+  my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';
+
+  # No query defined
+  unless ($index->query) {
+    return $cb->($index) if $cb;
+    return;
+  };
+
+  # Get query url
+  my $url = _query_url($index, @_);
+
+  # Cache based on URL
+  $index->_api_cache('total-' . $url->to_string);
+  my %param = @_;
+
+  # Set context based on parameter
+  $url->query({ context => $param{'context'} // 'paragraph' });
+
+  # Set path to search
+  $url->path('search');
+
+  # Check cache for total results
+  my $total_results;
+
+  if (!$index->no_cache &&
+	defined ($total_results = $c->chi->get($index->_api_cache))) {
+
+    # Set total results from cache
+    $index->total_results($total_results);
+    $c->app->log->debug('Get total result from cache');
+
+    # Set cutoff unless already set
+    $url->query({cutoff => 'true'}) unless defined $index->cutoff;
+  };
+
+  # Set api request for debugging
+  $index->api_request($url->to_string);
+
+  # Create new user agent and set timeout to 2 minutes
+  my $ua = $c->ua; # Mojo::UserAgent->new;
+  $ua->inactivity_timeout(120);
+
+  # Debugging
+  $c->app->log->debug('Search for ' . $index->api_request);
+
+  # Search non-blocking
+  if ($cb) {
+
+    $ua->get(
+      $url => sub {
+	my $tx = pop;
+	$self->_process_response('matches', $index, $tx);
+	weaken $index;
+	return $cb->($index);
+      });
+  }
+  # Search blocking
+  else {
+    my $tx = $ua->get($url);
+    $self->_process_response('matches', $index, $tx);
+    return $index;
+  };
+};
+
+
+# Trace query serialization
+sub trace {
+  my $self = shift;
+  my $index = shift;
+
+  # Get controller
+  my $c = $index->controller;
+
+  # If there is a callback, do async
+  my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';
+
+  my %param = @_;
+
+  # No query defined
+  unless ($index->query(delete $param{query})) {
+    return $cb->($index) if $cb;
+    return;
+  };
+
+  # Get query url
+  my $url = _query_url($index, @_);
+
+  $url->path('search');
+
+  # Create new user agent and set timeout to 30 seconds
+  my $ua = $c->ua; # Mojo::UserAgent->new;
+  $ua->inactivity_timeout(30);
+
+  # Build transaction
+  my $tx = $ua->build_tx(TRACE => $url);
+
+  # non-blocking
+  if ($cb) {
+    weaken $index;
+
+    # Trace non-blocking
+    $ua->start(
+      $tx => sub {
+	$self->_process_response('trace', $index, pop);
+	return $cb->($index);
+      });
+  }
+  # Trace blocking
+  else {
+    my $tx = $ua->start($url);
+    return $self->_process_response('trace', $index, $tx);
+  };
+};
+
+
+# Get match info
+sub match {
+  my $self = shift;
+  my $index = shift;
+
+  # Get controller
+  my $c = $index->controller;
+
+  # If there is a callback, do async
+  my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';
+
+  my %param = @_;
+
+  my $url = Mojo::URL->new($index->api);
+
+  # Use hash slice to create path
+  $url->path(join('/', 'corpus', @param{qw/corpus_id doc_id match_id/}, 'matchInfo'));
+
+  # Build match id
+  # $match = 'match-' . $corpus . '!' . $corpus . '_' . $doc . '-' . $match;
+
+  my %query;
+  $query{foundry} = $param{foundry};
+  $query{layer}   = $param{layer}   if defined $param{layer};
+  $query{spans}   = $param{spans} ? 'true' : 'false';
+
+  # Add query
+  $url->query(\%query);
+
+  $c->app->log->debug('Match info: ' . $url);
+
+  # Create new user agent and set timeout to 30 seconds
+  my $ua = $c->ua; # Mojo::UserAgent->new;
+  $ua->inactivity_timeout(30);
+
+  # non-blocking
+  if ($cb) {
+    weaken $index;
+    $ua->get(
+      $url => sub {
+	my $tx = pop;
+	$self->_process_response('match', $index, $tx);
+	return $cb->($index);
+      });
+  }
+
+  # Match info blocking
+  else {
+    my $tx = $ua->get($url);
+    return $self->_process_response('match', $index, $tx);
+  };
+};
+
+
+# Trace query serialization
+sub resource {
+  my $self = shift;
+  my $index = shift;
+
+  # Get controller
+  my $c = $index->controller;
+
+  # If there is a callback, do async
+  my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';
+
+  my %param = @_;
+
+  # Rename info endpoints regarding resource
+  my $type = $param{type} // 'collection';
+  $type = 'virtualcollection' if $type eq 'collection';
+
+  my $url = Mojo::URL->new($index->api)->path($type);
+
+  $c->app->log->debug('Get resource info on '. $url);
+
+  # Check for cached information
+  if (my $json = $c->chi->get($url->to_string)) {
+
+    # TODO: That's unfortunate, as it prohibits multiple resources
+    $c->app->log->debug('Get resource info from cache');
+    $c->stash('search.resource' => $json);
+    return $cb->($index) if $cb;
+    return $json;
+  };
+
+  $c->stash('search._resource_cache' => $url->to_string);
+
+  # Create new user agent and set timeout to 30 seconds
+  my $ua = $c->ua; # Mojo::UserAgent->new;
+  $ua->inactivity_timeout(30);
+
+  if ($cb) {
+    weaken $index;
+    $ua->get(
+      $url => sub {
+	$self->_process_response('resource', $index, pop);
+	return $cb->($index);
+      })
+  }
+  else {
+    my $tx = $ua->get($url);
+    $self->_process_response('resource', $index, $tx);
+  };
+};
+
+
+# Process response - especially error messages etc.
+sub _process_response {
+  my ($self, $type, $index, $tx) = @_;
+  my $c = $index->controller;
+
+  # An error has occurded
+  if (my $e = $tx->error) {
+    $c->notify(
+      error =>
+	($e->{code} ? $e->{code} . ': ' : '') .
+	  $e->{message} . ' (remote)'
+	);
+    return;
+  };
+
+  # Response was fine
+  if (my $res = $tx->success) {
+
+    # Set api response for debugging
+    $index->api_response($res->body) if $c->korap_test_port;
+
+    # Json failure
+    my $json;
+    unless ($json = $res->json) {
+      $c->notify(error => 'JSON response is invalid');
+      return;
+    };
+
+    # expected response for matches
+    if ($type eq 'matches') {
+      $self->_process_response_matches($index, $json);
+    }
+    elsif ($type eq 'trace') {
+      $self->_process_response_trace($index, $json);
+    }
+    elsif ($type eq 'match') {
+      $self->_process_response_match($index, $json);
+    }
+    elsif ($type eq 'resource') {
+      $self->_process_response_resource($index, $json);
+    };
+
+    return 1 if ref $json ne 'HASH';
+
+    # Add warnings (Legacy)
+    if ($json->{warning}) {
+      $json->{warning} =~ s/;\s+null$//;
+      $c->notify(warn => $json->{warning});
+    };
+
+    $self->_notify_on_error($c, 0, $json);
+  }
+
+  # Request failed
+  else {
+    $self->_notify_on_error($c, 1, $tx->res);
+  };
+  return 1;
+};
+
+
+sub _process_response_matches {
+  my ($self, $index, $json) = @_;
+
+  # Reformat benchmark counter
+  my $benchmark = $json->{benchmark};
+  if ($benchmark && $benchmark =~ s/\s+(m)?s$//) {
+    $benchmark = sprintf("%.2f", $benchmark) . ($1 ? $1 : '') . 's';
+  };
+
+  # Set benchmark
+  $index->benchmark($benchmark);
+
+  # Set time exceeded
+  if ($json->{timeExceeded} && $json->{timeExceeded} eq Mojo::JSON::true) {
+    $index->time_exceeded(1);
+  };
+
+  # Set result values
+  $index->items_per_page($json->{itemsPerPage});
+  $index->query_jsonld($json->{request}->{query});
+  $index->results(_map_matches($json->{matches}));
+
+  # Total results not set by stash
+  if ($index->total_results == -1) {
+
+    if ($json->{totalResults} && $json->{totalResults} > -1) {
+      my $c = $index->controller;
+
+      $c->app->log->debug('Cache total result');
+      $c->chi->set($index->_api_cache => $json->{totalResults}, '120min');
+      $index->total_results($json->{totalResults});
+    };
+  };
+};
+
+
+# Process query serialization response
+sub _process_response_match {
+  my ($self, $index, $json) = @_;
+  $index->results(_map_match($json));
+};
+
+
+# Process query serialization response
+sub _process_response_trace {
+  my ($self, $index, $json) = @_;
+  $index->query_jsonld($json);
+};
+
+sub _process_response_resource {
+  my ($self, $index, $json) = @_;
+  my $c = $index->controller;
+
+  # TODO: That's unfortunate, as it prohibits multiple resources
+  $c->stash('search.resource' => $json);
+  $c->app->log->debug('Cache resource info');
+  $c->chi->set($c->stash('search._resource_cache') => $json, '24 hours');
+};
+
+
+# Parse the error messages
+sub _notify_on_error {
+  my ($self, $c, $failure, $res) = @_;
+  my $json = $res;
+
+  my $log = $c->app->log;
+
+  # Check if the response is already json
+  if (blessed $res) {
+    $json = $res->json if blessed $res ne 'Mojo::JSON';
+  };
+
+  # Chec json response error message
+  if ($json) {
+    if ($json->{error}) {
+      # Temp
+      $json->{error} =~ s/;\s+null$//;
+      $c->notify(error => $json->{error});
+      return;
+    }
+
+    # New error messages
+    elsif ($json->{errstr}) {
+      # Temp
+      $json->{errstr} =~ s/;\s+null$//;
+      $c->notify(error => $json->{errstr});
+      return;
+    }
+
+    # policy service error messages
+    elsif ($json->{status}) {
+      $c->notify(error => 'Middleware error ' . $json->{status});
+      return;
+    };
+  };
+
+  # Doesn't matter what - there is a failure!
+  if ($failure) {
+    $c->notify(error => (
+      ($res->{code}    ? $res->{code} . ': ' : '') .
+      ($res->{message} ? $res->{message}     : 'Unknown error') .
+      ' (remote)'
+    ));
+  };
+};
+
+
+# Cleanup array of matches
+sub _map_matches {
+  return () unless $_[0];
+  map { _map_match($_) } @{ shift() };
+};
+
+
+# Cleanup single match
+sub _map_match {
+  my $x = shift or return;
+  $x->{ID} =~ s/^match\-[^!]+![^-]+-//;
+  $x->{docID} =~ s/^[^_]+_//;
+  $x;
+};
+
+
+sub _query_url {
+  my ($index, %param) = @_;
+
+  # Set cutoff from param
+  $index->cutoff(delete $param{cutoff});
+
+  # Set query language
+  $index->query_language(delete $param{query_language} // 'poliqarp');
+
+  # Should results be cached? Defaults to "yes"
+  $index->no_cache(1) if $param{no_cache};
+
+  # Init the query with stuff coming from the index
+  my %query;
+  $query{q}      = $index->query;
+  $query{ql}     = $index->query_language;
+  $query{page}   = $index->start_page if $index->start_page;
+  $query{count}  = $index->items_per_page if $index->items_per_page;
+  $query{cutoff} = 'true' if $index->cutoff;
+
+  # Todo: support corpus and collection
+  # Create query url
+  my $url = Mojo::URL->new($index->api);
+  $url->query(\%query);
+  return $url;
+};
+
+
+1;
+
+
+__END__
+
+=pod
+
+Additionally supported query parameters:
+- query_language
+- cutoff
+- no_cache
+
+Additional index attributes:
+- api
+- time_exceeded
+- api_request
+- api_response
+- benchmark
+- query_jsonld